Aerial panoramic oblique photography apparatus

ABSTRACT

An aerial panoramic oblique photography apparatus includes a pod body provided with at least two nadir cameras and a plurality of oblique cameras. The at least two nadir cameras are arranged in a transverse direction, and the shooting regions of adjacent nadir cameras of the at least two nadir cameras are partially overlapping. Since the aerial panoramic oblique photography apparatus is provided with at least two transversely arranged nadir cameras, a plurality of stripes of aerial images is obtained for each aerial oblique photo-shooting operation. This can increase photo-shooting efficiency, reduce the number of flight, and lower photo-shooting cost. The combination of at least two nadir cameras and a plurality of oblique cameras can capture texture of the sides of urban buildings from multiple angles. Three-dimensional real scenery model of a city can be established more efficiently and completely.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 15/458,048 filed on Mar. 14, 2017 which claims thebenefit of Hong Kong Patent Application No. 16104117.2, filed Apr. 11,2016 and Chinese patent application No. 201710062224.9 filed on Feb. 1,2017, the entire content of which is hereby incorporated by reference.

FIELD OF THE TECHNOLOGY

The present application relates to the field of aerial photographytechnology, and more particularly to an aerial panoramic obliquephotography apparatus.

BACKGROUND

Aerial panoramic oblique photography apparatus belongs to the technicalfield of aerial photogrammetry and aerial oblique photogrammetry. Aerialphotogrammetry relates to aerial photo-shooting and the use ofphotogrammetry technology to produce a variety of surveying and mappingproducts, such as digital terrain models, orthophoto maps and vectormaps. Aerial oblique photogrammetry is to obtain texture of the sides ofan object on the ground by taking photos at an oblique angle, and thenestablish a real urban three-dimensional model by the photogrammetrytechnology.

Aerial oblique photography is a breakthrough of the traditional aerialphotogrammetry. It takes photos of natural objects and man-madebuildings on the ground by a group of cameras arranged at differentangles. The existing aerial oblique photography apparatus is generallyin the form of a group of five cameras, including a nadir camera andfour oblique cameras. In consideration of the number of cameras, and thesize and weight of the apparatus, the oblique cameras will generally becommercial medium format cameras or full frame cameras.

Oblique cameras of the five-camera photography apparatus have limitedcoverage areas during operation. It is required to increase theoverlapping and sidelap in order to achieve a complete image-capturing.Overlapping depends on the speed of the aerial vehicle and the operatingspeed of the cameras. A five-camera combination generally requires nadircamera to have 80% overlapping in order to meet urban 3D modelrequirements. Sidelapping is the overlapping between each flight line. Afive-camera combination generally requires nadir cameras to have an 80%overlapping in order to meet the urban shooting requirements. Since thearea array of the medium or full frame camera is relatively small, andhigh-resolution images require a low-altitude flight, it will result inlow flight efficiency for a large overlapping photo-taking task. Thecost of flight will therefore be multiplied, and the number of imageswill be increased and repeated.

SUMMARY

An object of the aerial panoramic oblique photography apparatus of thepresent application is to provide an aerial panoramic obliquephotography apparatus which can improve operation efficiency and reducecosts by means of a novel arrangement of cameras.

According to one aspect, there is provided an aerial panoramic obliquephotography apparatus including a pod body provided with at least twonadir cameras and a plurality of oblique cameras, wherein the at leasttwo nadir cameras are arranged in a transverse direction, and shootingregions of adjacent nadir cameras of the at least two nadir cameras arepartially overlapping.

In one embodiment, an angle of a lens axis of each nadir camera from avertical direction is less than 10 degrees, and 30% to 60% of theshooting regions of the adjacent nadir cameras of the at least two nadircameras are overlapping.

In one embodiment, the lens axes of the at least two nadir cameras arelying on a same plane, and the lens axes of the adjacent nadir camerasare inclined in converging directions towards each other or inclined indiverging directions away from each other.

In one embodiment, a lens of the nadir camera is a fixed focus lens, andfocal length of the fixed focus lens of the nadir camera is 20 to 100mm.

In one embodiment, the plurality of oblique cameras is disposed aroundthe nadir cameras, and an angle of a lens axis of each oblique camerafrom a vertical direction is 30 to 60 degrees.

In one embodiment, a lens of the oblique camera is a fixed focus lens,and focal length of the fixed focus lens of the oblique camera is 35 to150 mm.

In one embodiment, the shooting regions of the nadir cameras andshooting regions of the oblique cameras transversely adjacent to thenadir cameras are partially overlapping.

In one embodiment, the pod body is a one-piece structure or a separablestructure.

In one embodiment, the pod body is a separable structure, and the podbody includes a left pod unit and a right pod unit, the left pod unitand the right pod unit each having one of the nadir cameras and aplurality of the oblique cameras.

In one embodiment, the number of the oblique cameras is eight or more,and the plurality of oblique cameras is provided on two levels, namelyan upper level and a lower level.

The aerial panoramic oblique photography apparatus of the presentapplication has the following beneficial effects. Since the aerialpanoramic oblique photography apparatus is provided with at least twotransversely arranged nadir cameras, a plurality of stripes of aerialimages is obtained for each aerial oblique photo-shooting operation.This can increase photo-shooting efficiency, reduce the number of flightlines, and lower the photo-shooting cost. The combination of at leasttwo nadir cameras and a plurality of oblique cameras, texture of thesides of urban buildings can be obtained from multiple angles.Three-dimensional real scenery model of a city can be established moreefficiently and completely.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific embodiments will now be described by way of example withreference to the accompanying drawings wherein:

FIG. 1a is a front view of an embodiment of the aerial panoramic obliquephotography apparatus of the present application.

FIG. 1b is a bottom view of the aerial panoramic oblique photographyapparatus shown in FIG. 1 a.

FIG. 1c is a left side view of the aerial panoramic oblique photographyapparatus shown in FIG. 1 a.

FIG. 2a is an illustrative diagram of two transversely overlappingimages formed by synchronous photo-shooting by two nadir cameras.

FIG. 2b is an illustrative diagram of the partially overlapping shootingregions of the two nadir cameras.

FIG. 2c is an image formed by synchronous photo-shooting of the twonadir cameras.

FIG. 3a is an illustrative diagram of lens axes of one way ofarrangement of two nadir cameras.

FIG. 3b is an illustrative diagram of lens axes of another way ofarrangement of two nadir cameras.

FIG. 4 is an illustrative diagram of the synchronized shooting coverageareas of the aerial panoramic oblique photography apparatus shown inFIG. 1 a.

FIG. 5 is an illustrative diagram of synchronized shooting by 12 camerasof the aerial panoramic oblique photography apparatus shown in FIG. 1 a.

FIG. 6a is an illustrative diagram of the partially overlapping shootingregions of a nadir camera and an oblique camera adjacent to the nadircamera.

FIG. 6b is an illustrative diagram of an image formed by synchronizedshooting of a nadir camera and an oblique camera adjacent to the nadircamera of the aerial panoramic oblique photography apparatus shown inFIG. 1 a.

FIG. 7 is an illustrative diagram of the coverage areas of the aerialpanoramic oblique photography apparatus at a flight altitude of 800meters.

DETAILED DESCRIPTION

To have a clear understanding of the technical features, objects andeffects of the aerial panoramic oblique photography apparatus of thepresent application, specific embodiments will now be described indetail with reference to the accompanying drawings.

Embodiments of the aerial panoramic oblique photography apparatus of thepresent application are described below in detail. These embodiments areshown in the accompanying drawings Like reference numerals representinglike parts with like functions are used throughout the drawings.

It should be appreciated that in the description of the aerial panoramicoblique photography apparatus of the present application, the terms“front”, “rear”, “top”, “bottom”, “upper end”, “lower end”, “upperportion”, “lower portion”, etc. refer to the orientation or position ofa structure as it is oriented and positioned in the drawings. Thoseterms are used to simplify the description and do not indicate or implythat the structure must have a specific orientation or operate in aspecific position. Those terms should not be considered as limiting.

FIGS. 1a and 1b show a schematic view of an embodiment of an aerialpanoramic oblique photography apparatus of the present application. Inthis embodiment, the aerial panoramic oblique photography apparatus mayinclude a pod body 1 having a separable structure. The pod body 1 mayinclude a left pod unit 1 a and a right pod unit 1 b. The left pod unit1 a may be provided with one nadir camera 21 a and five oblique cameras31 a. The right pod unit 1 b may also be provided with one nadir camera21 b and five oblique cameras 31 b. That is to say, in the presentembodiment, the aerial panoramic oblique photography apparatus may havea total of 12 cameras, including two nadir cameras 21 a, 21 b, and 10oblique cameras 31 a, 31 b. The left and right pod units 1 a and 1 b maybe fixed together to form a single unit, as depicted in FIGS. 1a to 1 c.The left pod unit 1 a and the right pod unit 1 b may be separatelyprovided on two sides of an aerial vehicle.

As shown in FIG. 1 b, the two nadir cameras 21 a, 21 b of the aerialpanoramic oblique photography apparatus of the present application maybe arranged in a transverse direction. The longitudinal direction refersto the flight direction of the aerial vehicle, and the transversedirection is the direction perpendicular to the longitudinal direction.The transverse direction and the longitudinal direction may be locatedon a same horizontal plane. The nadir cameras can be used for shootingphotos in a downward direction. The nadir cameras can be used to producephotogrammetric surveying results, such as stereo-mapping, line drawingmaps, orthophoto maps, etc. The shooting regions of the two nadircameras 21 a, 21 b may be partially overlapping. As shown in FIGS. 2a to2c , the shooting region 211 of the nadir camera 21 a may partiallyoverlap with the shooting region 212 of the nadir camera 21 b. Theoverlapping region is designated by reference numeral 213. The lenses ofthe nadir cameras 21 a, 21 b may be fixed focus lenses or zoom lenses,preferably fixed focus lenses with a focal length of 20 to 100 mm.Referring to FIGS. 3a and 3b , the lenses of the nadir cameras 21 a, 21b may have a certain inclination. That is to say, the lens axes 201, 202of the nadir cameras 21 a, 21 b may be orientated at an angle α withrespect to the vertical direction. The angle α is preferably smallerthan 10 degrees so as to it can meet the requirement of orthophotoproduction by the nadir cameras 21 a, 21 b. The lens axes 201, 202 ofthe nadir cameras 21 a, 21 b may be inclined in converging directionstowards each other, as shown in FIG. 3a ; or the lens axes 201, 202 ofthe nadir cameras 21 a, 21 b may be inclined in diverging directionsaway from each other, as shown in FIG. 3b . In the embodiment shown inFIG. 1 b, the lens axes of the nadir cameras 21 a, 21 b may be inclinedin converging directions towards each other. The two nadir cameras 21 a,21 b may be referred to as a dual camera. The lens axes of the nadircameras 21 a, 21 b is preferably provided on a same plane, morepreferably on a plane perpendicular to the longitudinal direction. It ispreferable that the shooting regions 211 and 212 of the nadir cameras 21a and 21 b have an overlap of 30% to 60%. That means the area of theoverlapping area 213 is 30% to 60% of the area of the shooting regions211 and 212 of the nadir cameras 21 a and 21 b.

In one embodiment, the nadir cameras 21 a, 21 b may employ a full-framecamera of 50 million pixels and the focal length of lens is 35 mm. Theshooting regions 211, 212 of the nadir cameras 21 a, 21 b may have anoverlap of 50%. FIG. 2c shows an image formed by synchronousphoto-shooting of the two nadir cameras 21 a, 21 b. Using the two nadircameras 21 a, 21 b, two strips of aerial images can be obtained for eachaerial photo-shooting operation. This can reduce the necessary flyingtime and the operating cost.

As shown in FIGS. 1a to 1 c, the oblique cameras 31 a and 31 b can beinclined by inclining devices so that they can produce photo-shooting ata certain inclination angle with respect to the vertical direction. Theoblique cameras 31 a, 31 b can be used to capture texture of the sidesof an object on the surface of a land, such as various man-madebuildings and natural scenery, etc. The angle between the lens axes ofthe oblique cameras 31 a and 31 b and the vertical direction may be30-60 degrees. In the present embodiment, ten oblique cameras 31 a, 31 bmay be employed, i.e. five oblique cameras on the left pod unit 1 a, andfive oblique cameras on the right pod unit 1 b. In other embodiments,the number of oblique cameras may not be limited to the above-mentionednumber. It may have a plurality of oblique cameras, preferably eight ormore. The oblique cameras may be provided around the nadir cameras ofthe photography apparatus so as to achieve panoramic oblique coverageduring synchronous photo-shooting. The number of cameras for panoramacoverage can be determined according to the angle of field of view ofthe cameras. The lenses of the oblique cameras may be fixed focus lensesor zoom lenses, preferably fixed focus lenses, and the focal length ofthe fixed focus lenses is preferably 35 to 150 mm. In anotherembodiment, the oblique cameras can be medium format cameras with fixedfocus lenses having a focal length of 55 mm. The angle of the long sideof the field of view may be about 51.8 degrees. During synchronousshooting, at least eight cameras may be required for panoramic coverage.In another embodiment, the oblique cameras may be fixed focus lenseswith a focal length of 80 mm. The angle of the long side of the field ofview may be about 36.9 degrees. During synchronous shooting, at leastten cameras may be required for panoramic coverage. The oblique camerascan also be full-frame cameras with fixed focus lenses having a focallength of 50 mm. The angle of the long side of the field of view may beabout 39.2 degrees. Then during synchronous shooting, ten obliquecameras may be required for panoramic coverage.

FIG. 4 is an illustrative diagram of the synchronous shooting coverageareas of the aerial panoramic oblique photography apparatus of thepresent embodiment. The aerial panoramic oblique photography apparatusmay employ twelve full-frame cameras, including two nadir cameras 21 a,21 b with 35 mm fixed focus lenses, and ten oblique cameras 31 a and 31b with 50 mm fixed focus lenses. A total of twelve full-frame camerasmay constitute the aerial panoramic oblique photography apparatus.Shooting regions of the nadir cameras 21 a and 21 b are represented byreference numeral 211, 212, and shooting regions of the oblique cameras31 a and 31 b are represented by reference numeral 311, 312. FIG. 5 isan illustrative diagram of synchronous shooting by twelve cameras.

Due to the large number of cameras in the aerial panoramic obliquephotography apparatus, the camera in the aerial panorama obliquephotography apparatus can adopt a layered or horizontal design so as tomake the design more compact. The advantage of a layered design is tominimize the transverse width of the photography apparatus. Theadvantage of a horizontal design is to minimize the height of thephotography apparatus. In the embodiment shown in FIG. 1 a, the obliquecameras 31 a, 31 b can be provided in two layers. The first layer mayhave six oblique cameras 31 a, 31 b and the second layer may have fouroblique cameras 31 a, 31 b. The left pod unit 1 a and the right pod unit1 b of the present embodiment can be integrated or separately mounted.For separate mounting, the entire apparatus may be divided into twounits, each having a separate camera synchronization system, storage,USB 3.0 data interface, POS AV™ system, and power system, etc.

In FIGS. 6a and 6b , the shooting regions 211, 212 of the nadir cameras21 a, 21 b and the transversely adjacent shooting regions 311, 312 ofthe oblique cameras 31 a, 31 b may be partially overlapped, and can forman integrated strip of images at the time of synchronous shooting. FIG.6b is an illustrative diagram of an image formed by synchronous shootingby two nadir cameras 21 a, 21 b and two oblique cameras 31 a, 31 btransversely adjacent to the nadir cameras of the aerial panoramicoblique photography apparatus of the present embodiment. The applicationof strip-type shooting may include railroad, road, river, coastline,power line, oil pipeline, etc. It can adopt the aerial panoramic obliquephotography apparatus of the present embodiment, and satisfy thestrip-type flight requirements. As shown in FIG. 7, the width ofcoverage of the aerial panoramic oblique photography apparatus can be2,595 meters when flying at a flight altitude of 800 meters.

During aerial panoramic oblique shooting, a flight management system canplan the flight path and shooting location according to the flightmission range. During execution of a mission, the flight managementsystem can control the cameras of the aerial panoramic obliquephotography apparatus to take photos according to the flight planthrough connection to navigation data provided by the POS AV™ system. Acamera synchronous shooting system can control synchronized shooting ofthe cameras when the flight management system sends out a shootingsignal. Each of the nadir cameras and oblique cameras of the aerialpanorama oblique photography apparatus can have an independent cameratrigger device. The nadir cameras may use TTL trigger signals, and maysimultaneously give exposure signals to the oblique cameras. The centerexposure pulse of each camera can be returned to the dual POS AV™system. Each POS AV™ system may need to simultaneously receive six eventsignals.

Each camera may have an internal storage of more than 512 GB. This canguarantee the storage for more than 10 K images. The entire system mayhave an internal storage of up to 120 k images. Image data can beconnected to an external computer through USB3.0 Hub for downloading.Each camera may have a separate USB3.0 cable connection for the settingof camera parameters through external computer equipment. The aerialpanoramic oblique photography apparatus may adopt broadband 9-36 VDCpower supply which is suitable for various unmanned aerial vehiclebatteries, car batteries, aircraft power sources, etc. Indicator lightsmay include LED navigation status indicator, nadir camera indicators,and oblique camera indicators for the POS AV™ in each set of cameras.Input/output interface of each set of cameras may include: 1 set of TNCGLASS antenna interface, power input aviation LEMO interface, 2 sets ofRS232 for GLASS differential interface.

The pod body of the aerial panoramic oblique photography apparatus ofthe present application is not limited to the above-described separablestructure, but may have an integrated one-piece structure. The nadircameras and the oblique cameras can be provided on an integrated podbody. The pod body may also be provided with a combination ofdirectional and positioning system (IMU/GNSS system or Applanix POS AV™system), aircraft installation components, electronic control unit,storage unit, and flight management system.

The number of the nadir cameras of the aerial panoramic obliquephotography apparatus of the present application is not limited to two,but may be two or more, i.e. at least two. The nadir cameras may bearranged in a transverse direction, and the shooting regions of adjacentnadir cameras may be partially overlapping. When three nadir cameras areused, three strips of aerial photos can be produced for each flight ofphoto-taking. When the number of nadir cameras is more than two, theshooting regions of adjacent nadir cameras of the nadir cameras may havean overlapping of 30% to 60%.

The aerial panoramic oblique photography apparatus of the presentapplication may have at least two nadir cameras arranged in a transversedirection. A plurality of strips of nadir route images can be obtainedwhen each aerial oblique photo-taking is performed. This can improveshooting efficiency, reduce the number of flight and lower the shootingcost. The combination of at least two nadir cameras and a plurality ofoblique cameras can obtain texture of the sides of an urban buildingfrom multiple angles, and can more effectively and completely establishurban three-dimensional real scenery model.

Specific embodiments have been described above with reference to theaccompanying drawings. However, the present application is not limitedto the above specific embodiments. The above specific embodiments aremerely illustrative and should not be considered as limiting. It shouldbe noted that, upon reading the above disclosure, a person skilled inthe art can make various other changes or modifications withoutdeparting from the scope of the appended claims.

What is claimed is:
 1. An aerial panoramic oblique photography apparatuscomprising a pod body comprising a left pod unit and a right pod unit;at least two nadir cameras arranged in a transverse directionperpendicular to a bisecting plane between the left pod unit and theright pod unit, wherein at least one nadir camera is provided on theleft pod unit and at least one nadir camera is provided on the right podunit; and a plurality of oblique cameras disposed on the left pod unitand the right pod unit at an upper level and a lower level; wherein anangle of a lens axis of each nadir camera from a vertical direction isgreater than 0 degree and less than 10 degrees, and an angle of a lensaxis of each oblique camera from the vertical direction is 30 to 60degrees, the vertical direction is a nadir direction from the lens ofeach nadir or oblique camera and perpendicular to a separation planebetween the upper level and the lower level, the vertical direction, thetransverse direction and a direction of an intersection line of thebisecting plane and the separation plane are perpendicular to eachother; and wherein shooting regions of adjacent nadir cameras of the atleast two nadir cameras are partially overlapping.
 2. The aerialpanoramic oblique photography apparatus as claimed in claim 1, wherein30% to 60% of the shooting regions of the adjacent nadir cameras of theat least two nadir cameras are overlapping.
 3. The aerial panoramicoblique photography apparatus as claimed in claim 1, wherein theshooting regions of the nadir cameras and shooting regions of theoblique cameras transversely adjacent to the nadir cameras are partiallyoverlapping.
 4. The aerial panoramic oblique photography apparatus asclaimed in claim 1, wherein the lens axes of the at least two nadircameras are lying on a same plane.
 5. The aerial panoramic obliquephotography apparatus as claimed in claim 1, wherein the lens axes ofthe adjacent nadir cameras are inclined in converging directions towardseach other.
 6. The aerial panoramic oblique photography apparatus asclaimed in claim 1, wherein the lens axes of the adjacent nadir camerasare inclined in diverging directions away from each other.
 7. The aerialpanoramic oblique photography apparatus as claimed in claim 1, wherein alens of the nadir camera is a fixed focus lens, and focal length of thefixed focus lens of the nadir camera is 20 to 100 mm.
 8. The aerialpanoramic oblique photography apparatus as claimed in claim 1, wherein alens of the oblique camera is a fixed focus lens, and focal length ofthe fixed focus lens of the oblique camera is 35 to 150 mm.
 9. Theaerial panoramic oblique photography apparatus as claimed in claim 8,wherein the focal length of the fixed focus lens of the oblique camerais 55 mm and an angle of a long side of a field of view of the obliquecamera is about 51.8 degrees.
 10. The aerial panoramic obliquephotography apparatus as claimed in claim 8, wherein the focal length ofthe fixed focus lens of the oblique camera is 80 mm and an angle of along side of a field of view of the oblique camera is about 36.9degrees.
 11. The aerial panoramic oblique photography apparatus asclaimed in claim 8, wherein the focal length of the fixed focus lens ofthe oblique camera is 50 mm and an angle of a long side of a field ofview of the oblique camera is about 39.2 degrees.
 12. The aerialpanoramic oblique photography apparatus as claimed in claim 1, whereinthe number of the oblique cameras is eight or more.
 13. The aerialpanoramic oblique photography apparatus as claimed in claim 1, whereinthe pod body is a separable structure.
 14. The aerial panoramic obliquephotography apparatus as claimed in claim 1, wherein the plurality ofoblique cameras disposed around the at least two nadir cameras.